Abstract: Abstract Novel biphenyl-containing polyimide (PI) solution based on pyromellitic dianhydride (PMDA)/3,3’,4,4’-biphenyl-tetracarboxylic dianhydride (BPDA)/o-tolidine(OTOL) were synthesized via co-polymerization. Its PI fibers are produced through dry-jet wet-spinning technique. These fibers are characterized with field emission scanning electron microscopy (FESEM), wide-angle X-ray diffraction (WAXD), fiber mechanical property tester, dynamic mechanical analyzer (DMA), thermogravimetric analyzer (TGA). Particularly, effects of draw ratio on morphology, orientation, mechanical properties and thermal properties of PI fibers are discussed. PI fibers have smooth surface, relatively uniform diameter, and skin-core structure in cross-section. The diameter and filament of PI fibers decrease and the degree of orientation increases with draw ratio. Crystallinity of these fibers is very low. The tensile strength and tensile modulus of the PI fibers can reach 2.95 GPa and100.0 GPa when draw ratio is 2.8. Generally, 10% weight loss of these PI fibers corresponds to temperatures above 580oC and it indicates that these fibers possess excellent thermal stability under nitrogen atmosphere Two relaxations above room temperature can be found in DMA curves. The glass transition temperature (Tg) of PI fibers is above 340 oC.